Which JSON Schema rules are supported?

The draft-07 keywords ajv 8 implements, which covers everything the example schema uses: type, required, enum, pattern, length and numeric limits, items and additionalProperties.

Do I have to write a schema from scratch?

No. Start from the product-feed schema that loads with the tool and change the properties, patterns and limits to match your own contract.

Does it check that the content is any good?

No. It checks shape and constraints — presence, type, format, range. Whether the copy is accurate or on-brand is a reading task, and the console plus a reviewer take that part.

Toolbox · Structured output

Schema output validator

A JSON Schema on one side, a form generated from it on the other: paste the model's output and see exactly which rule it breaks.

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A schema turns a prose rulebook into a form

The rules for a feed record usually live in a style document: SKU in this format, title under seventy characters, price above zero, no fields we did not ask for. Written as JSON Schema they become executable, and react-jsonschema-form renders the input form from the schema itself, so the form and the rules can never drift apart.

Paste the model's JSON and the same form fills in with it. Every error lands on the field that caused it instead of arriving as one wall of text at the end of a pipeline.

The business rules that fit in a schema

Required fields, types, enumerations, string patterns and lengths, numeric ranges, and array limits all validate cleanly. additionalProperties: false is the one worth adding by default: it catches the invented field an LLM adds when it decides the output wants a subtitle nobody asked for.

Cross-field rules — end date after start date, discount below price — belong in oneOf or dependencies, and they are where a schema starts to read like code. Keep those few and documented.

Where a schema stops

A schema can insist a title is under seventy characters and that a description is longer than 120. It cannot tell you the title describes the wrong product, or that the description is true. Structural validity is necessary, and it is not the review.

Questions about this tool

Which JSON Schema rules are supported?: The draft-07 keywords ajv 8 implements, which covers everything the example schema uses: type, required, enum, pattern, length and numeric limits, items and additionalProperties.
Do I have to write a schema from scratch?: No. Start from the product-feed schema that loads with the tool and change the properties, patterns and limits to match your own contract.
Does it check that the content is any good?: No. It checks shape and constraints — presence, type, format, range. Whether the copy is accurate or on-brand is a reading task, and the console plus a reviewer take that part.

Toolbox

Fix the prose here, then check what the prose cannot show.

The console runs structural, claim and formatting checks on the same draft, and a named reviewer takes on anything with consequences.

Run a check Request a specialist